Effect of antenna gain and group delay variations on pulse-preserving capabilities of ultrawideband antennas

Pulse-preserving capabilities of ultrawideband (UWB) antennas, which are measured in terms of two parameters-the fidelity factor and the pulse width stretch ratio, are analyzed with respect to variations of the antenna gain and the group delay of the radiated field. With the degrees of the gain and the group delay variations quantified by their respective standard deviations from constant values, Monte-Carlo simulations are performed to evaluate the effect of different gain and group delay functions using randomly generated Gaussian profiles. The means and the standard variations of the two performance parameter distributions are monitored and their two-dimensional profiles are specifically obtained for UWB antennas operating in 3.1-10.6 GHz. The analysis also demonstrates the use of the fidelity factor and the pulse width stretch ratio as useful characterizing parameters for UWB antennas.